GOES-12 visible images (above) showed that a well-defined lake breeze developed along the western portion of Lake Superior during the afternoon hours on 22 June 2009. The MODIS Sea Surface Temperature (SST) product from 2 days earlier (below) indicated that SST values in the much of the middle of the lake were still in the low 40s F (blue color enhancement) — and Buoy 45006 was actually reporting a SST value of 39 F on 22 June. In northern Wisconsin, note the large surface air temperature gradient that existed between Port Wing (station identifier PNGW3) which remained in the upper 40s F and Ashland (station identifier KASX) which rose into the low 80s F!

MODIS Sea Surface Temperature product

Farther to the south, GOES-12 visible imagery also showed that a Lake Michigan lake breeze was moving inland across southeastern Wisconsin and northeastern Illinois (below).

Moderate southwesterly flow aloft over the Rocky Mountains was aiding in the formation of mountain waves across much of Colorado and parts of the adjacent states on 22 June 2009. AWIPS comparisons of the 1-km resolution MODIS 6.7 Âµm water vapor image with the corresponding 4-km resolution GOES-12 6.5 Âµm water vapor image (above) and the 8-km resolution GOES-11 6.7 Âµm water vapor image (below) demonstrated the value of better spatial resolution for detecting such mesoscale features.

MODIS 6.7 Âµm and GOES-11 6.7 Âµm water vapor images

The appearance of these banded “mountain wave signatures” on water vapor imagery indicates the potential for clear air turbulence in those areas; however, there were no pilot reports of turbulence until 13:02 UTC near Fort Collins (at an altitude of 15,000 feet). An animation of the GOES-12 6.5 Âµm water vapor imagery (below) also showed the presence of a lee-side cold frontal gravity wave, which could be seen propagating southward across eastern Colorado and western Kansas. In fact, a small packet of waves could be seen along and behind the leading edge of this lee-side cold frontal gravity wave on the MODIS water vapor images above — surface winds behind this front had gusted to 36 knots at McCook, Nebraska (station identifier KMCK) and 20 knots at Goodland, Kansas (station identifier KGLD).